Cerebrospinal fluid (CSF) Aβ42, total tau and phosphorylated tau (p-tau) are well-defined diagnostic markers for Alzheimer's disease (AD). There has been no previous report of the use of these markers in the diagnosis of AD in patients with chronic kidney disease (CKD). We would like to report our preliminary findings on these biomarkers in three patients with renal failure. One patient with a clinical diagnosis of AD showed elevated CSF tau, p-tau 181, and decreased Aβ42 levels, within a similar range as in local Chinese AD patients without renal impairment. The other two delirious patients, who did not have a clinical diagnosis of AD, showed normal CSF biomarkers. We found that the diagnosis of AD with CSF biomarkers appears to be useful in renal failure patients. But our results need to be confirmed in a larger study, comparing these CSF biomarkers in AD vs. non-AD patients with concomitant CKD.